Phased array antenna system including a modular control and monitoring architecture

ABSTRACT

A phased array antenna system includes a plurality of radio frequency (RF) tile sub-arrays. Each RF tile sub-array includes a multiplicity of RF elements, a tile control integrated circuit, a multiplicity of RF integrated circuits and a configuration storage device. The configuration storage device stores data including calibration and configuration information that is unique to the RF tile sub-array and the tile control integrated circuit. The multiplicity of RF integrated circuits, the multiplicity of RF elements, and the configuration storage device are disposed on a single associated RF tile sub-array. The system also includes an antenna controller configured to process data for steering or tracking one or more RF beams by the multiplicity of RF elements. The calibration and configuration information that is unique to the RF tile sub-array is downloaded from the configuration storage device through the tile control integrated circuit to an RF element compensation table.

FIELD

The present disclosure relates to antennas and antenna systems, and moreparticularly to a phased array antenna system including a modularcontrol and monitoring architecture.

BACKGROUND

Phased array antennas include a multiplicity of antenna elements thatmay be arranged in a predetermined pattern. For example, the antennaelements may be arranged in rows and columns, although otherarrangements may also be used depending upon the purpose, application orother parameters. Each of the antenna elements needs to be controlled tocontrol a direction of propagation of a radio frequency (RF) beamcreated or transmitted by the phased array antenna. Controlling adirection of transmission or reception of RF beams or signals by thephased array antenna may be referred to as beam steering or tracking.Electronically steered phased array antennas typically require a greatdeal of data calculation and processing to create and control the RFbeam. The control signals then have to be distributed to the antennaelements which typically require a significant number of electrical dataconnections. This can limit the expandability of the phased arrayantenna, particularly in applications where there may be size and spacelimitations such on aircraft or spacecraft. Additionally, phased arrayantenna applications on aircraft or spacecraft may require a level ofperformance with management of multiple RF beams simultaneously. Beamsteering or tracking performance may be required to support a wide rangeof vehicle angular rates and accelerations. Tracking performance ispreferably independent of the number of RF elements, RF beams or thesize of transmit and receive apertures.

SUMMARY

In accordance with an embodiment, a phased array antenna system mayinclude a plurality of radio frequency (RF) tile sub-arrays arranged ina certain pattern to define an RF aperture. Each RF tile sub-array mayinclude a multiplicity of RF elements and each RF element may beseparately controlled for steering or tracking an RF beam generated orreceived by the RF element. Each RF tile sub-array further includes atile control integrated circuit, a multiplicity of RF integratedcircuits and a configuration storage device connected to the tilecontrol integrated circuit. The configuration storage device stores datacomprising calibration and configuration information that is unique tothe RF tile sub-array and the tile control integrated circuit. Themultiplicity of RF integrated circuits, the multiplicity of RF elements,and the configuration storage device are disposed on a single associatedRF tile sub-array. The tile control integrated circuit is operativelyconnected to each of the multiplicity of RF integrated circuits on thesingle associated RF tile sub-array and each RF integrated circuit isoperatively connected to one or more RF elements of the multiplicity ofRF elements on the single associated RF tile sub-array. The phased arrayantenna system may also include an antenna controller configured toprocess data for steering or tracking one or more RF beams by themultiplicity of RF elements. The antenna controller may additionallyinclude a plurality of aperture state machines. An aperture statemachine may be associated with each RF tile sub-array for controllingoperation of the associated RF tile sub-array. The aperture statemachine associated with each RF tile sub-array includes an RF elementcompensation table. The calibration and configuration information thatis unique to the RF tile sub-array is downloaded from the configurationstorage device through the tile control integrated circuit to the RFelement compensation table. The phased array antenna system may furtherinclude a plurality of RF tile buses. One RF tile bus may operativelycouple each aperture state machine to the associated RF tile sub-array.

In accordance with another embodiment, a phased array antenna system mayinclude a plurality of radio frequency (RF) tile sub-arrays arranged ina certain pattern to define an RF aperture. Each RF tile sub-array mayinclude a multiplicity of RF elements and each RF element may beseparately controllable for steering or tracking an RF beam. Each RFtile sub-array includes a configuration storage device that stores dataincluding calibration and configuration information that is unique toeach RF tile sub-array. Each RF sub-array may also include amultiplicity of RF integrated circuits. Each RF integrated circuit isoperatively connected to one or more RF elements. The RF tile sub-arraymay also include a tile control integrated circuit configured toindividually control the multiplicity of RF elements. The RF tilesub-array may additionally include a clock and serial bus matrix thatoperatively connects the multiplicity of RF integrated circuits to thetile control integrated circuit. The tile control integrated circuit,the multiplicity of RF integrated circuits, the multiplicity of RFelements, and the configuration storage device are disposed on a singleassociated RF tile sub-array. The phased array antenna system may alsoinclude an antenna controller configured to process data for steering ortracking one or more RF beams generated or received by the multiplicityof RF elements. The antenna controller includes a plurality of aperturestate machines. An aperture state machine is associated with each RFtile sub-array for controlling operation of the associated RF tilesub-array. The aperture state machine associated with each RF tilesub-array includes an RF element compensation table. The calibration andconfiguration information that is unique to the RF tile sub-array isdownloaded from the configuration storage device through the tilecontrol integrated circuit to the RF element compensation table. The RFtile sub-array may additionally include a plurality of RF tile buses.One RF tile bus may be associated with each RF tile sub-array thatoperatively couples the associated RF tile sub-array to the antennacontroller.

In accordance with a further embodiment, a method for controlling andmonitoring a phased array antenna system may include receiving data foruse in steering or tracking a radio frequency (RF) beam. The method mayalso include downloading calibration and configuration information fromeach RF tile sub-array of a plurality of RF tile sub-arrays to an RFelement compensation table of a respective aperture state machineassociated with each RF tile sub-array. The calibration andconfiguration information is unique to each RF tile sub-array and thecalibration and configuration information is downloaded from aconfiguration storage device on each RF tile sub-array through a tilecontrol integrated circuit on each RF tile sub-array to the RF elementcompensation table. The method may also include concurrently andseparately processing the data to provide unique control data to each RFtile sub-array of a plurality of RF tile sub-arrays. Each RF tilesub-array may include a multiplicity of RF elements. A multiplicity ofRF integrated circuits are operatively connected to one or more of themultiplicity of RF elements. A tile control integrated circuit isoperatively connected to each of the multiplicity of RF integratedcircuits. The multiplicity of RF elements, the multiplicity of RFintegrated circuits, the tile control integrated circuit and theconfiguration storage device are disposed on a single associated RF tilesub-array. Each RF element may be separately controlled for steering ortracking the RF beam generated by the RF element or received by the RFelement based on the unique control data. The method may further includetransmitting each unique control data to a corresponding RF tilesub-array over an RF tile bus of a plurality of RF tile buses. One RFtile bus of the plurality of RF tile buses is associated with each RFtile sub-array of the plurality of RF tile sub-arrays.

In accordance with another embodiment or any of the previousembodiments, the antenna controller may further include an antennamanager. The antenna manager may be configured to receive data forsteering or tracking the one or more RF beams and to transmit controland status data and beam pointing information to one of the aperturestate machines in response to RF elements of the RF tile sub-arrayassociated with the one aperture state machine being selected for usefor steering or tracking the one or more RF beams.

In accordance with another embodiment or any of the previousembodiments, each aperture state machine may be configured forprocessing RF element phase data for the associated RF tile sub-arrayusing spherical coordinates and a phase compensation function. The RFelement phase data allows the associated RF tile sub-array to steer ortrack the one or more RF beams. The plurality of aperture state machinesprovides concurrent processing of RF tile sub-array phase data from asteering or tracking solution to loading the RF element phase data inthe associated RF tile sub-arrays.

In accordance with another embodiment or any of the previousembodiments, each aperture state machine may include an RF compensationtable that receives information from the antenna manager for use indetermining a steering or tracking solution and determines RF elementcompensation data based on the information. Each aperture state machinemay also include a tile multi-beam phase and true time delay calculatorpipeline that receives RF element compensation data from the RF elementcompensation table and beam point information from the antenna manager.The tile multi-beam phase and true time delay calculator determines aphase shift value for each RF element of the associated RF sub-arraybased on the RF element compensation information and the beam pointinginformation. The aperture state machine may also include a tile physicallayer (PHY) coupling the tile multi-beam phase and true time delaycalculator pipeline to an associated RF tile bus.

BRIEF DESCRIPTION OF THE DRAWINGS

The following detailed description of embodiments refers to theaccompanying drawings, which illustrate specific embodiments of thedisclosure. Other embodiments having different structures and operationsdo not depart from the scope of the present disclosure.

FIG. 1 is a block schematic diagram of an example of a phased arrayantenna system including a modular control and monitoring architecturein accordance with an embodiment of the present disclosure.

FIG. 2 is a block schematic diagram of an example of an aperture statemachine for controlling operation of an RF tile sub-array of an antennaaperture of a phased array antenna system in accordance with anembodiment of the present disclosure.

FIG. 3 is a detailed block schematic diagram illustrating an example ofa tile connector of an RF tile sub-array in accordance with anembodiment of the present disclosure.

FIG. 4 is a block schematic diagram of an example of an RF tilesub-array in accordance with an embodiment of the present disclosure.

FIG. 5 is a representation of an example of an RF application-specificintegrated circuit (ASIC) data access priority protocol in accordancewith an embodiment of the present disclosure.

FIG. 6 is a flow chart of an example of a method for determining a phaseshift for each RF element for steering or tracking an RF beam inaccordance with an embodiment of the present disclosure.

FIG. 7 is a flow chart of an example of a method for controlling andmonitoring a phased array antenna system in accordance with anembodiment of the present disclosure.

FIG. 8 is a block schematic diagram of a vehicle including a phasedarray antenna system in accordance with an embodiment of the presentdisclosure.

DETAILED DESCRIPTION

The following detailed description of embodiments refers to theaccompanying drawings, which illustrate specific embodiments of thedisclosure. Other embodiments having different structures and operationsdo not depart from the scope of the present disclosure. Like referencenumerals may refer to the same element or component in the differentdrawings.

Certain terminology is used herein for convenience only and is not to betaken as a limitation on the embodiments described. For example, wordssuch as “proximal”, “distal”, “top”, “bottom”, “upper,” “lower,” “left,”“right,” “horizontal,” “vertical,” “upward,” and “downward”, etc.,merely describe the configuration shown in the figures or relativepositions used with reference to the orientation of the figures beingdescribed. Because components of embodiments can be positioned in anumber of different orientations, the directional terminology is usedfor purposes of illustration and is in no way limiting. It is to beunderstood that other embodiments may be utilized and structural orlogical changes may be made without departing from the scope of thepresent invention. The following detailed description, therefore, is notto be taken in a limiting sense, and the scope of the present inventionis defined by the appended claims.

FIG. 1 is a block schematic diagram of an example of a phased arrayantenna system 100 including a modular control and monitoringarchitecture 102 in accordance with an embodiment of the presentdisclosure. The phased array antenna system 100 may be a low profilephased array antenna system that may be used on a vehicle, such as forexample, an aircraft or aerospace vehicle wherein the low profile phasedarray antenna or antenna system 100 will provide negligible if any dragor effect on the performance of the vehicle. The phased array antennasystem 100 may include a plurality of radio frequency (RF) tilesub-arrays 104 that may be arranged in a certain pattern to define an RFaperture 106. The plurality of RF tile sub-arrays 104 may include afirst group of RF tile sub-arrays 104 that may define a receive aperture106 a and a second group of RF tile sub-arrays 104 that may define atransmit aperture 106 b. The RF tile sub-arrays 104 of the receiveaperture 106 a and the RF tile sub-arrays 104 of the transmit aperture106 b may have the same structure. The first group of RF tile sub-arrays104 of receive aperture 106 a and the second group of RF tile sub-arrays104 of transmit aperture 106 b may each include an equal number of RFtile sub-arrays 104 or a different number of RF tile sub-arrays 104.Each RF tile sub-array 104 may include a multiplicity of RF elements 112for transmitting and receiving RF signals. Each RF element 112 may beseparately controllable for steering or tracking an RF beam 114, 116generated or received by the RF element 112 or group of RF elements 112.An RF element 112 or group of RF elements 112 of the receive aperture106 a may track a single received RF beam 114 a or multiple received RFbeams 114 a-114 n. An RF element 112 or group of RF elements 112 of thetransmit aperture 106 b may steer a single transmitted RF beam 116 a ormultiple transmitted RF beams 116 a-116 d. The RF beams 114, 116 mayinclude RF signals.

Each RF tile sub-array 104 may also include a multiplicity of RFintegrated circuits or application-specific integrated circuits (ASICs)118. An RF ASIC 118 may be associated with each RF element 112 forcontrolling operation of the RF element 112. Each RF ASIC 118 may beoperatively coupled to one, two or four RF elements 112 for controllingoperation of the associated single RF element 112, or dual or quad RFelements 112.

Each RF tile sub-array 104 may also include a tile control integratedcircuit or ASIC 120 for addressing and controlling operation of each ofthe RF ASICs 118. Each tile control ASIC 120 may be implemented in anapplication specific integrated circuit (ASIC), field programmable gatearray (FPGA) or complex programmable logic device (CPLD). The tilecontrol ASIC 120 may be operatively coupled to each of the RF ASICs 118by an RF ASIC bus matrix 122 which may also be referred to herein as aclock and data serial bus matrix. The tile control ASIC 120 may addressa specific RF ASIC 118 by a clock line and a data line as described inmore detail herein. An example of an RF tile sub-array that may be usedfor each of the RF tile sub-arrays 104 will be described in more detailwith reference to FIG. 4.

The phased array antenna system 100 may also include an antennacontroller 124. The antenna controller 124 may be configured to processdata received by the antenna controller 124 for steering or tracking theone or more RF beams 114-116 by the multiplicity of RF elements 112. Theantenna controller 124 may include an antenna manager 126 and aplurality of aperture state machines 128 operatively coupled to theantenna manager 126. The plurality of aperture state machines 128 mayinclude a group of receive aperture state machines 128 a and a group oftransmit aperture state machines 128 b. An aperture state machine 128may be associated with each RF tile sub-array 104 for controllingoperation of the associated RF tile sub-array 104. An example of anaperture state machine that may be used for each of the aperture statemachines 128 will be described with reference to FIG. 2.

The phased array antenna system 100 may also include a plurality of RFtile buses 130. One RF tile bus 130 may operatively couple each aperturestate machine 128 to its associated RF tile sub-array 104. Accordingly,each receive aperture state machine 128 a may be operatively coupled bya single RF tile bus 130 a to a respective RF tile sub-array 104 of thereceive aperture 106 a. Similarly, each transmit aperture state machine128 b may be operatively coupled by a single RF tile bus 130 b to arespective RF tile sub-array 104 of the transmit aperture 106 b. Each RFtile bus 130 may be a half-duplex synchronous serial bus for RF element112 data transport to reduce electrical connections to each RF tilesub-array 104 to four pins as described in more detail with reference toFIG. 3

The antenna manager 126 may be configured to receive data 132 forsteering or tracking the one or more RF beams 114-116 and to transmitcontrol and status data and beam pointing information to one of theaperture state machines 128 in response to the RF elements 112 of the RFtile sub-array 104 associated with the one aperture state machine 128being selected for use for steering or tracking the one or more RF beams114-116. Examples of the data 132 received by the antenna manager 126may include but is not necessarily limited to a geographic location ofthe vehicle, such as global positioning system (GPS) information,antenna state information, navigational information, such as vehiclespeed, directional heading, rates of angular motion of the vehicle orother vehicle attitude or state information, RF element fault status, RFelement isolation data, and any other information that may be useful forsteering or tracking the RF beam or beams 114-116. The data 132 may bereceived from different sensors on a vehicle. The antenna manager 126may process the received data and may transmit control data to one ormore receive aperture state machines 128 a or to one or more transmitaperture state machines 128 b depending upon which RF tile sub-array orsub-arrays 104 are being controlled by the control data. Control datamay be sent by the antenna manager 126 to a selected one or more receiveaperture state machine 128 a depending upon which RF tile sub-array orarrays 104 of the receive aperture 106 a are being controlled fortracking one or more received RF beams 114 a-114 n. Similarly, controldata may be sent by the antenna manager 126 to a selected one or moretransmit aperture state machine 128 b depending upon which RF tilesub-array or sub-arrays 104 of the transmit aperture 106 b are beingcontrolled for steering a transmitted RF beam or beams 116 a-116 n.

The antenna manager 126 may also receive status and/or other informationfrom the respective RF tile sub-arrays 104 of the receive aperture 106 aand the transmit aperture 106 b via the RF tile bus 130 and aperturestate machine 128 associated with the particular RF tile sub-array 104.The control data and status information exchanged between the antennamanager 126 and the receive aperture state machines 128 a may include areceive (RX) RF tile direct memory access (DMA) 134. Similarly, thecontrol and status information exchanged between the antenna manager 126and the transmit aperture state machines 128 b may include a transmit(TX) RF tile DMA 136. An example of an RX RF tile DMA 134 and a TX RFtile DMA 136 will be described in more detail with reference to FIG. 2.

Each aperture state machine 128 may be configured for processing RFelement phase data for the associated RF tile sub-array 104 using beampointing information in spherical coordinates and a phase compensationfunction. The RF element phase data may allow the associated RF tilesub-array 104 to steer or track the one or more RF beams 114/116. Theplurality of aperture state machines 128 provides concurrent processingof RF tile sub-array phase data from a steering or tracking solution toloading the RF element phase data in the associated RF tile sub-arrays104.

FIG. 2 is a block schematic diagram of an example of an aperture statemachine 200 for controlling operation of an RF tile sub-array of anantenna aperture of a phased array antenna system in accordance with anembodiment of the present disclosure. The exemplary aperture statemachine 200 may be used for each of the receive aperture state machines128 a and transmit aperture state machines 128 b in FIG. 1. The aperturestate machine 200 may receive an aperture control and status DMA stack202. The aperture control and status DMA stack 202 may correspond to anRX RF tile DMA 134 in FIG. 1 if the aperture state machine 200 is areceive aperture state machine 128 a. The aperture control and statusDMA stack 202 may correspond to a TX RF tile DMA 136 in FIG. 1 if theaperture state machine 200 is a transmit aperture state machine 128 b.The aperture control and status DMA stack 202 may include a tile writeDMA space 204, a tile compensation table DMA space 206 and a tile readDMA space 208. The tile write DMA space 204 may include RF tilesub-array command and direct write data for controlling operations of aparticular RF tile sub-array 104 associated with the aperture statemachine 200. The tile compensation table DMA space 206 may include datafor use in determining phase compensation or phase delay values for theRF elements 112 of the particular RF sub-array 104 associated with theaperture state machine 200 similar to that described herein withreference to FIG. 7. The tile read DMA space 208 may include data fromthe particular RF sub-array 104 associated with the aperture statemachine 200.

The aperture state machine 200 may include an RF element compensationtable 210 that may receive information from the antenna manager 126 foruse in determining a steering or tracking solution and for determiningRF element phase compensation data based on the information. The RFelement compensation table 210 may receive data or information in thetile compensation table DMA space 206 of the aperture control and statusDMA stack 202. The data or information in the tile compensation tableDMA space 206 may be used by the RF element compensation table 210 todetermine phase compensation values for particular RF elements 112 ofthe RF tile sub-array 104 associated with the aperture state machine 200for steering the transmitted RF beams 116 a-116 n or tracking thereceived RF beams 114 a-114 n.

The RF compensation table 210 compensates for differences in delay(phase) between each RF element's 112 interface to a received ortransmitted electromagnetic wave or RF signal in free space to a pointin the RF circuitry of the RF tile sub-array 104 where the RF signalsfrom all RF elements 112 are combined. The RF compensation table 210 maybe referred to more specifically as a phase compensation table. Thecontents of an RF compensation table 210 or phase compensation table maybe unique from one manufactured RF tile sub-array 104 to another, due tonormal manufacturing process variation in a circuit board of theparticular RF tile sub-array 104 and in the RF ASIC's 118 installed onthe particular RF tile sub-array 104. This results in a need to storethis unique compensation/calibration data in non-volatile memory(configuration storage device 422 in FIG. 4), for each RF tile sub-array104, during factory test/calibration, so the uniquecompensation/calibration data may be recalled and used for phasecalculation in the antenna controller 124 during operation. Other uniquecompensation tables may be included in the same non-volatile memory,including but not limited to attenuator settings and bias settings forthe internal amplifiers in the element RF ASIC's 118.

The aperture state machine 200 may also include a tile multi-beam phaseand true time delay (TTD) calculator pipeline 212. The multi-beam phaseand TTD calculator pipeline 212 may receive RF element compensation datafrom the RF element compensation table 210 and beam point information214 from the antenna manager 126. The tile multi-beam phase and TTDcalculator pipeline 212 may determine a phase shift value for each RFelement 112 of the RF sub-array 104 associated with the aperture statemachine 200 based on the RF element compensation information from the RFelement compensation table 210 and the beam pointing information 214.The tile multi-beam phase and TTD calculator pipeline 212 may use amethod of phase calculation similar to that described in U.S. Pat. No.6,606,056, entitled “Beam Steering Controller for a Curved SurfacePhased Array Antenna,” which is assigned to the same assignee as thepresent application and is incorporated herein by reference in itsentirety. An exemplary method of phase calculation similar to thatdescribed in U.S. Pat. No. 6,606,056 that may be used by the tilemulti-beam phase and TTD calculator pipeline 212 will be described withreference to FIG. 6. The method may be replicated for each beam in amulti-beam application. The phase and TTD calculator pipeline 212 may bescaled to any number of RF tile sub-arrays 104 and any practical numberof RF elements 112 per RF tile sub-array 104. Because each RF tilesub-array's phase information is processed concurrently, the processingtime increases only with the number of RF elements 112 per RF tilesub-array 104. RF elements 112 up to 128 per RF tile sub-array 104 maybe processed in a nominal two millisecond beam update time. The antennacontroller 124 and RF sub-arrays 104 are configured to provide RF beamupdates at a cycle time of about two milliseconds or less and RF beamsteering or tracking performance for vehicle angular rates greater thanabout 60 degrees per second.

The aperture state machine 200 may additionally include a tile physicallayer (PHY) interface 216. The tile PHY interface 216 may operativelycouple the tile multi-beam phase and TTD calculator pipeline 212 to anassociated RF tile bus 130. The tile PHY interface 216 may convert thecontrol data to an appropriate electrical waveform for transmission overthe RF tile bus 130 to the RF tile sub-array 104 associated with theaperture state machine 200 and that is operatively coupled to theaperture state machine 200 by the associated RF tile bus 130. An exampleof an appropriate electrical waveform may be an electrical waveformcompatible with Telecommunications Industry Association/ElectronicsIndustries Alliance (TIA/EIA) technical standard RS-422/485, Low VoltageDifferential Signaling (LVDS) or TIA/EIA technical standard 644,Ethernet (Institute of Electrical and Electronic Engineers technicalstandard IEEE-802.3xxxx), or other data transmission method congruentwith the physical media and distance.

The aperture state machine 200 may additionally include a tile commandand direct write module 218. The tile command and direct write module218 may receive data or information in the tile write DMA space 204 ofthe aperture control and status DMA stack 202 from the antenna manager126. The tile command and direct write module 218 may be connected tothe tile PHY interface 216 for sending the tile command and writeinformation to the RF tile sub-array 104 associated with the aperturestate machine 200 over the associated RF tile bus 130.

The aperture state machine 200 may also include a tile status andread-back module 220 for receiving status and read-back information fromthe RF tile sub-array 104 associated with the aperture state machine200. The status and read-back information may be received from the RFtile sub-array 104 by the tile PHY interface 216 over the associated RFtile bus 130. The tile status and read-back information may be sent bythe tile status and read-back module 220 to the antenna manager 126using the tile read DMA space 208 of the aperture control and status DMAstack 202. The aperture state machine 200 and the associated RF tile bus130 provide direct memory access from the antenna manager 126 to the RFtile sub-array 104 that is operatively coupled to the aperture statemachine 200 by the associated RF tile bus 130.

The aperture state machines 200 may be implemented in a configurablelogic device or devices, such as for example a field programmable gatearray (FPGA).

FIG. 3 is a block schematic diagram illustrating an example of a tileconnector 300 of an RF tile sub-array 104 in accordance with anembodiment of the present disclosure. The tile connector 300 may includea tile bus connection 302 for connecting to the RF tile bus 130. Thetile bus connector may include two ports or pins, a tile datainput/output port 304 or pin and tile clock input port 306 or pin. Thetile data input/output port 304 may be operatively connected to the tilecontrol ASIC 120 by a tile data input/output link 308 or line (TILE DATAI/O). The tile clock input port 306 may be operatively connected to thetile control ASIC 120 by a tile clock link 310 or line (TILE CLK). Aspreviously described, the RF tile bus 130 may be a half-duplexsynchronous serial bus.

The tile connector 300 may also include an RF signal port 312 or pin fortransmitting and receiving RF signals between the RF tile sub-array 104and a transceiver 314. Induced noise by the RF signals may be minimizedin the tile connector 300 by using balanced differential electricalsignals. For example, LVDS or technical standard TIA/EIA 644 or similardata transmission standard may be used to minimize induced noise. Thetile connector 300 may further include an RF tile power and returns port316 or pin for providing electrical power to the RF tile sub-array 104from an RF tile power and returns module 318. Accordingly, electricalconnections to each RF tile sub-array 104 may be limited to four portsor pins. All control and status data to the RF tile sub-array 104 mayflow through the tile connector 300. Because the tile connector 300 hasonly four pins or ports, the tile connector 300 may be very compactwhich permits the tile connector 300 to be placed at an optimal locationfor RF signal connectivity for each of the plurality of RF tilesub-arrays 104. For example, the tile connector 300 may be placed indifferent locations on the RF tile-sub-array 104 or around a perimeterof the RF tile sub-array 104 for different RF tile sub-arrays 104 toprovide optimal connectivity and routing of RF signal wiring.

FIG. 4 is a detailed block schematic diagram of an exemplary RF tilesub-array 104 in accordance with an embodiment of the presentdisclosure. As previously described, the RF tile sub-array 104 mayinclude a tile control integrated circuit or tile control ASIC 120. Atile data input/output link 308 or line (Tile Data I/O) connects thetile control ASIC 120 to the associated RF tile bus 130 via a tileconnector 300 (FIG. 3). A tile clock link 310 or line (TILE CLK) alsoconnects the tile control ASIC 120 to the RF tile bus 130 via the tileconnector 300. The tile control ASIC 120 may be configured toindividually control a multiplicity of RF elements 112 (FIG. 1) inresponse to data received from the antenna controller 124 over the RFtile bus 130.

The RF tile sub-array 104 may also include a multiplicity of RFintegrated circuits or RF ASICs 118. Each RF ASIC 118 may be operativelycoupled to one, two or four RF elements 112 (FIG. 1) for controllingoperation of the operatively connected RF element or elements 112.

Each RF tile sub-array 104 may have a predetermined shape. For example,each RF tile sub-array 104 may be substantially square or rectangularshaped as shown in the exemplary RF tile sub-array 104 in FIG. 4.Although the RF tile sub-array 104 may not be perfectly square orrectangular and may define other geometric shapes, such as triangular,hexagonal, rhomboid, etc. depending upon the use or application of thephased array antenna system 100. The multiplicity of RF ASICs 118 may bearranged in quadrants 412 on the RF tile sub-array 104 similar to thatillustrated in the exemplary embodiment in FIG. 4. Each quadrant 412 ofRF ASICs 118 may be operatively connected to the tile control ASIC 120by a clock and data serial bus matrix 414 that may limit a number ofinterconnect pins on each RF ASIC 118 to four. Each clock and dataserial bus matrix 414 may include two clock lines (CLK #A and CLK #B)418 a, 418 b. The RF tile sub-array 104 may include at least one truetime delay (TTD) circuit 416 for each RF beam 114, 116 for controllingthe phase delay of the entire RF tile sub-array 104. TTD circuit 416 isused to extend the bandwidth of the RF aperture 106 (FIG. 1). One TTDcircuit 416 may be used per RF beam 114, 116 per RF tile sub-array 104.

The RF ASICs 118 and TTD circuit 416 or circuits 416 may be selectivelyaddressed by the two clock lines 418 a and 418 b and plurality of datalines 420 of each clock and data serial bus matrix 414. The clock lines418 a and 418 b may be serially connected to each RF ASIC 118 and TTDcircuit 416, if present, of each quadrant 412. In the exemplaryembodiment of FIG. 4, each data line 420 may serial connect two RF ASICs118. In other embodiments, more than two RF ASICs 118 may be seriallyconnected requiring additional clock lines for each additional RF ASIC118. The RF ASICs 118 and TTD circuit 416, if present, in the quadrant412 may be connected as party line slaves with the tile control ASIC 120as the master.

The RF tile sub-array 104 may also include a configuration storagedevice 422. The configuration storage device 422 may be any type of datastorage device or memory. The configuration storage device 422 may storedata comprising calibration and configuration information that may beunique to the particular RF tile sub-array 104. The multiplicity of RFelements 112 of a particular RF tile sub-array 104 may be calibrated inphase with one another during initial manufacturing to support acorrelated beam function during operation of the phased array antennasystem 100. The unique phase calibration and compensation data for eachRF tile element 112 of the particular RF tile sub-array 104 may bestored in the configuration storage device 422. This allows repair orreplacement of the RF tile sub-array 104 without recalibration of theentire phased array antenna system 100. Additionally, the RF elementphase calibration and compensation data may be downloaded to the antennacontroller 124 (FIG. 1) and used in the beam forming phase computations.

Accordingly, the RF tile sub-array 104 is a self-contained RF sub-array104 in a single assembly that contains a minimum amount ofcontrol-status implementation and relies on an antenna controller 124(FIG. 1) for processing the RF element 112 phase data. The RF element112 phase processing is contained in the antenna control function in theantenna controller 124 and is described with reference to FIG. 6 herein.The antenna control-monitoring architecture 102 described herein isextensible to virtually any practical number of RF tile sub-arrays 104while maintaining a low-cost implementation.

FIG. 5 is a representation of an RF ASIC data access priority protocol500 in accordance with an embodiment of the present disclosure. Each RFASIC 118 (FIG. 4) may use a three-level data access protocol 502 forprioritizing data access to each RF element 112 (FIG. 1). A first levelof data access priority 504 is reserved for highest priority data.Examples of highest priority data may include but is not necessarilylimited to beam phase, TTD loading and similar data for controllingoperation and/or tracking or steering of the RF element 112 which may beaccessed every beam update cycle. A second level of data access priority506 or intermediate level of data access priority may provide access tointermediate level data. Examples of intermediate level data may includebut is not necessarily limited to commonly used status data, load-onceconfiguration settings or similar data. A third level of data accesspriority 508 or lowest level data access priority may provide access tolonger or slow device status that may require multiple accesses toretrieve. Second and third level data access priority 506 and 508 may beinterleaved over multiple RF beam update cycles. Accordingly, highestpriority data having the first level of data access priority 504 may betransmitted or accessed without interference by data in the second andthird level data access priority 506 and 508. This multi-level accessscheme supports efficient RF element connectivity to the antennacontroller 124 and provides greater status for fault detection andisolation compared to current phase array antenna systems.

FIG. 6 is a flow chart of an example of a method 600 for determining aphase shift for each RF element for steering or tracking an RF beam inaccordance with an embodiment of the present disclosure. The method 600is similar to the phase calculation described in U.S. Pat. No. 6,606,056and may be embodied in and performed by the tile multi-beam phase andTTD calculator pipeline 212 in FIG. 2. The method 600 may be replicatedfor each RF beam 114/116 in a multi-beam application such as the phasedarray antenna system 100. In block 602, RF beam pointing information andRF element phase compensation information may be received. Similar tothat previously described, the RF beam pointing information and RFelement compensation information may be received by the tile multi-beamphase and TTD calculator pipeline 212 in FIG. 2 from the antenna manage126. The RF beam pointing information may be in spherical coordinateswhere Theta (θ) is an angle of elevation and Phi (ϕ) is an azimuthangle.

In block 604, dx, dy and dz wavelength shift values may be determinedfrom the beam pointing information. The dx, dy and dz wavelength shiftvalues may each correspond to a fraction of a wavelength shift perwavelength displacement along a respective X, Y and Z axis of an antennaaperture of a phased array antenna based on the beam pointinginformation. The values may be represented according to the followingequations:dx=sin(θ)*cos(ϕ)  Eq. 1dy=sin(θ)*sin(ϕ)  Eq. 2dz=cos(θ)  Eq. 3

In block 606, a delay value for each RF element of the RF tile sub-arraymay be determined. The delay value for each RF element may be determinedaccording to equation 4:Element_Delay=dx*ΔX+dy*ΔY+dz*ΔZ  Eq. 4

ΔX, ΔY and ΔZ are the X, Y and Z displacements (in wavelengths) of eachRF element 112 from a predefined center of the antenna aperture. TheElement_Delay is a 2's complement signed delay in wavelengths requiredfor the signal from a given RF element to a predetermined center of thephased array antenna, in order to sum in-phase with signals from otherRF elements of the array.

In block 608, an actual phase shift value to be applied to each RFelement may be determined. The actual phase shift value to be applied toeach RF element may be determined according to equation 5:Element_Phase_Shift=Truncate_to_1_wavelength(Round_to_N_bit(Element_Delay))  Eq. 5

Where N is the number of bits used to control the phase shifter in orderto produce 2^(N) phase states. The Element Phase Shift may be an actualphase shift value, in modulo 1 wavelength, loaded into each RF element.The Element Phase Shift value may be truncated such that only the N bitsto the right of the binary point are kept. This may provide a precisionof 2^(−N) (i.e., ½^(N)) wavelengths for the actual phase shift values.

In block 610, the phase shift data may be sent to the RF tile sub-arrayfor application to the particular RF elements.

FIG. 7 is a flow chart of an example of a method 700 for controlling andmonitoring a phased array antenna system in accordance with anembodiment of the present disclosure. The method 700 may be embodied inand performed by the phased array antenna system 100 in FIG. 1. In block702, data for use in steering or tracking a radio frequency (RF) beammay be received. The data may be received by an antenna controllersimilar to antenna controller 124 in FIG. 1. As previously described,the examples of the data may include but is not necessarily limited to ageographic location of the vehicle, such as global positioning system(GPS) information, antenna state information, navigational information,such as vehicle speed, directional heading, rates of angular motion ofthe vehicle or other vehicle attitude or state information, RF elementfault status, RF element isolation data, and any other information thatmay be useful for steering or tracking an RF beam or beams such as RFbeams 114-116 in FIG.

In block 704, the data may be concurrently and separately processed toprovide unique control data to each RF tile sub-array of a plurality ofRF tile sub-arrays. Similar to that previously described, each RF tilesub-array may include a multiplicity of RF elements and each RF elementmay be separately controllable for steering or tracking the RF beamgenerated by the RF element or received by the RF element based on theunique control data.

In block 706, each unique control data may be transmitted to acorresponding RF tile sub-array over an RF tile bus of a plurality of RFtile buses. In block 708, the unique control data may be processed by atile control integrated circuit or ASIC of the RF tile sub-array toprovide individual control information corresponding to each RF elementof the RF tile sub-array.

In block 710, the individual control information may be transmitted toan RF integrated circuit or RF ASIC associated with each RF element. TheRF ASIC may use the individual control information to control theassociated RF element for steering or tracking the RF beam.

FIG. 8 is a block schematic diagram of a vehicle 800 including a phasedarray antenna system 802 in accordance with an embodiment of the presentdisclosure. The phased array antenna system 802 may be similar to thephased array antenna system 100 described with reference to FIG. 1.

A transceiver 804 may be operatively coupled to the phased array antennasystem 802 and the transceiver 804 may be configured for transmittingand receiving RF signals using the phased array antenna system 802. Thetransceiver 804 may include a transmitter 806 for transmitting RFsignals using the phased array antenna system 802 and a receiver 808 forreceiving RF signals using the phased array antenna system 802.

The transceiver 804 may also include an antenna direction control module810 or controller configured for steering or tracking RF beams carryingRF signals that are either transmitted or received by the phased arrayantenna system 802.

A user interface 812 may also be operatively coupled to the transceiver804 for controlling operation of the transceiver 804.

The flowchart and block diagrams in the Figures illustrate thearchitecture, functionality, and operation of possible implementationsof systems, methods, and computer program products according to variousembodiments of the present invention. In this regard, each block in theflowchart or block diagrams may represent a module, segment, or portionof instructions, which comprises one or more executable instructions forimplementing the specified logical function(s). In some alternativeimplementations, the functions noted in the block may occur out of theorder noted in the figures. For example, two blocks shown in successionmay, in fact, be executed substantially concurrently, or the blocks maysometimes be executed in the reverse order, depending upon thefunctionality involved. It will also be noted that each block of theblock diagrams and/or flowchart illustration, and combinations of blocksin the block diagrams and/or flowchart illustration, can be implementedby special purpose hardware-based systems that perform the specifiedfunctions or acts or carry out combinations of special purpose hardwareand computer instructions.

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of embodiments ofthe invention. As used herein, the singular forms “a”, “an” and “the”are intended to include the plural forms as well, unless the contextclearly indicates otherwise. It will be further understood that theterms “comprises” and/or “comprising,” when used in this specification,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof.

The corresponding structures, materials, acts, and equivalents of allmeans or step plus function elements in the claims below are intended toinclude any structure, material, or act for performing the function incombination with other claimed elements as specifically claimed. Thedescription of the present invention has been presented for purposes ofillustration and description, but is not intended to be exhaustive orlimited to embodiments of the invention in the form disclosed. Manymodifications and variations will be apparent to those of ordinary skillin the art without departing from the scope and spirit of embodiments ofthe invention. The embodiment was chosen and described in order to bestexplain the principles of embodiments of the invention and the practicalapplication, and to enable others of ordinary skill in the art tounderstand embodiments of the invention for various embodiments withvarious modifications as are suited to the particular use contemplated.

Although specific embodiments have been illustrated and describedherein, those of ordinary skill in the art appreciate that anyarrangement which is calculated to achieve the same purpose may besubstituted for the specific embodiments shown and that embodiments ofthe invention have other applications in other environments. Thisapplication is intended to cover any adaptations or variations of thepresent invention. The following claims are in no way intended to limitthe scope of embodiments of the invention to the specific embodimentsdescribed herein.

What is claimed is:
 1. A phased array antenna system (100), comprising:a plurality of radio frequency (RF) tile sub-arrays (104) arranged in acertain pattern to define an RF aperture (106), each RF tile sub-array(104) comprising a multiplicity of RF elements (112), each RF element(112) being separately controllable for steering or tracking an RF beam(114, 116) generated or received by the RF element (112), and each RFtile sub-array further comprising a tile control integrated circuit, amultiplicity of RF integrated circuits and a configuration storagedevice connected to the tile control integrated circuit, wherein theconfiguration storage device stores data comprising calibration andconfiguration information that is unique to the RF tile sub-array andthe tile control integrated circuit, the multiplicity of RF integratedcircuits, the multiplicity of RF elements, and the configuration storagedevice are disposed on a single associated RF tile sub-array, the tilecontrol integrated circuit is operatively connected to each of themultiplicity of RF integrated circuits on the single associated RF tilesub-array and each RF integrated circuit is operatively connected to oneor more RF elements of the multiplicity of RF elements on the singleassociated RF tile sub-array; an antenna controller (124) configured toprocess data for steering or tracking one or more RF beams by themultiplicity of RF elements, the antenna controller comprising aplurality of aperture state machines (128 a, 128 b), an aperture statemachine being associated with each RF tile sub-array for controllingoperation of the associated RF tile sub-array, the aperture statemachine associated with each RF tile sub-array comprising an RF elementcompensation table, wherein the calibration and configurationinformation that is unique to the RF tile sub-array is downloaded fromthe configuration storage device through the tile control integratedcircuit to the RF element compensation table; and a plurality of RF tilebuses (130), one RF tile bus operatively coupling each aperture statemachine (128 a, 128 b) to the associated RF tile sub-array (104).
 2. Thephased array antenna system (100) of claim 1, wherein the antennacontroller (124) further comprises an antenna manager (126), the antennamanager being configured to receive data for steering or tracking theone or more RF beams (114, 116) and to transmit control and status dataand beam pointing information to one of the aperture state machines (128a, 128 b) in response to RF elements (112) of the RF tile sub-array(104) associated with the one aperture state machine (128 a, 128 b)being selected for use for steering or tracking the one or more RF beams(114, 116).
 3. The phased array antenna system (100) of claim 2, whereineach aperture state machine (128, 200) is configured for processing RFelement phase data for the associated RF tile sub-array using beampointing information (214) and RF element phase compensation data (602),the RF element phase data allows the associated RF tile sub-array tosteer or track the one or more RF beams, the plurality of aperture statemachines provides concurrent processing of RF tile sub-array phase datafrom a steering or tracking solution to loading the RF element phasedata in the associated RF tile sub-arrays.
 4. The phased array antennasystem (100) of claim 2, wherein each aperture state machine (128, 200)comprises: the RF compensation table (210) that receives informationfrom the antenna manager (126) for use in determining a steering ortracking solution and determines RF element compensation data based onthe information; a tile multi-beam phase and true time delay calculatorpipeline (212) that receives RF element compensation data from the RFelement compensation table and beam point information from the antennamanager, wherein the tile multi-beam phase and true time delaycalculator pipeline determines a delay for each RF element of theassociated RF sub-array based on the RF element compensation data andthe beam pointing information; and a tile physical layer (PHY) interface(216) coupling the tile multi-beam phase and true time delay calculatorpipeline to an associated RF tile bus.
 5. The phased array antennasystem (100) of claim 4, wherein each aperture state machine (128, 200)further comprises: a tile command and direct write module (218) forreceiving tile command and write information in a tile write DMA space(204) from the antenna manager (126), the tile command and direct writemodule being connected to the tile PHY interface (216) for sending thetile command and write information to the associated RF tile sub-array(104) via the associated RF tile bus (130); and a tile status andread-back module (220) for receiving status and read-back informationfrom the associated RF tile sub-array (104) via the associated RF tilebus (130), the tile status and read-back module (220) being connected tothe tile PHY interface (216).
 6. The phased array antenna system (100)of claim 1, wherein the aperture state machine (128, 200) and anassociated RF tile bus provide a direct memory access from an antennamanager of the antenna controller to the associated RF tile sub-array.7. The phased array antenna system (100) of claim 1, wherein each RFtile sub-array (104) comprises a tile connector (300), the tileconnector comprising: a tile bus connection (302) including a tile datainput/output port (304) and a tile clock input port (306); an RF signalport (312) for receiving and transmitting RF signals from and to the RFtile sub-array; and an RF tile power and returns port (316) forproviding electrical power to the RF tile sub-array.
 8. The phased arrayantenna system (100) of claim 7, wherein each RF tile sub-array (104)further comprises: a tile data input/output link (308) that connects thetile control integrated circuit to an associated RF tile bus (130) viathe tile connector (300); and a tile clock link (310) that connects thetile control integrated circuit (120) to the RF tile bus (130) via thetile connector (300), wherein the tile control integrated circuit (120)is configured to individually control the multiplicity of RF elements(112) in response to data received from the antenna controller (124)over the RF tile bus (130).
 9. The phased array antenna system (100) ofclaim 8, wherein each RF integrated circuit (118) is operativelyconnected to one, two or four RF elements (112) for controllingoperation of the operatively connected RF element or RF elements (112).10. The phased array antenna system (100) of claim 9, wherein each RFtile sub-array (104) comprises a predetermined shape and themultiplicity of RF integrated circuits (118) are arranged in quadrants(412) on the RF tile sub-array (104) and each quadrant of RF integratedcircuits are operatively connected to the tile control integratedcircuit by a clock and data serial bus matrix (414) that limits a numberof interconnect pins on each RF integrated circuit to four.
 11. Thephased array antenna system (100) of claim 10, wherein each RF tilesub-array (104) comprises at least one true time delay circuit (416) perRF beam (114, 116).
 12. The phased array antenna system (100) of claim11, wherein the RF integrated circuits (118) and the true time delaycircuit (416) are connected as party line slaves with the tile controlintegrated circuit as master.
 13. The phased array antenna system ofclaim 1, wherein the tile control integrated circuit is located at acentral location on the RF tile sub-array and the multiplicity of RFintegrated circuits are arranged in quadrants surrounding the tilecontrol integrated circuit on the RF tile sub-array.
 14. The phasedarray antenna system (100) of claim 1, wherein the multiplicity of RFelements (112) of a particular RF tile sub-array (104) are calibrated inphase with one another to support a correlated beam function and thecalibration and configuration information stored in the configurationstorage device (422) allows replacement of the RF tile sub-array withoutrecalibration of the phased array antenna system (100).
 15. The phasedarray antenna system (100) of claim 1, wherein the antenna controller(124) and RF sub-arrays (104) are configured to provide RF beam updatesat a cycle time of about 2 milliseconds or less and RF beam steering ortracking performance for vehicle angular rates greater than about 60degrees per second.
 16. A phased array antenna system (100), comprising:a plurality of radio frequency (RF) tile sub-arrays (104) arranged in acertain pattern to define an RF aperture (106), each RF tile sub-arraycomprising: a multiplicity of RF elements (112), each RF element beingseparately controllable for steering or tracking an RF beam, whereineach RF tile sub-array comprises a configuration storage device (422)that stores data comprising calibration and configuration informationthat is unique to each RF tile sub-array; a multiplicity of RFintegrated circuits, each RF integrated circuit being operativelyconnected to one or more RF elements; a tile control integrated circuit(120) configured to individually control the multiplicity of RF elements(112); a clock and serial bus matrix (414) that operatively connects themultiplicity of RF integrated circuits to the tile control integratedcircuit, wherein the tile control integrated circuit, the multiplicityof RF integrated circuits, the multiplicity of RF elements, and theconfiguration storage device are disposed on a single associated RF tilesub-array; an antenna controller (124) configured to process data forsteering or tracking one or more RF beams generated or received by themultiplicity of RF elements, wherein the antenna controller (124)comprises a plurality of aperture state machines (128 a, 128 b, 200), anaperture state machine being associated with each RF tile sub-array(104) for controlling operation of the associated RF tile sub-array(104), the aperture state machine associated with each RF tile sub-arraycomprising an RF element compensation table, wherein the calibration andconfiguration information that is unique to the RF tile sub-array isdownloaded from the configuration storage device through the tilecontrol integrated circuit to the RF element compensation table; and aplurality of RF tile buses (130), one RF tile bus (130) associated witheach RF tile sub-array (104) that operatively couples the associated RFtile sub-array (104) to the antenna controller (124).
 17. The phasedarray antenna system (100) of claim 16, wherein the antenna controller(124) comprises a plurality of aperture state machines (128 a, 128 b,200), an aperture state machine being associated with each RF tilesub-array (104) for controlling operation of the associated RF tilesub-array (104), the one RF tile bus (130) operatively coupling eachaperture state machine (128 a, 128 b, 200) to the associated RF tilesub-array (104).
 18. A method for controlling and monitoring a phasedarray antenna system (700), comprising: receiving data for use insteering or tracking a radio frequency (RF) beam (702); downloadingcalibration and configuration information from each RF tile sub-array ofa plurality of RF tile sub-arrays to an RF element compensation table ofa respective aperture state machine associated with each RF tilesub-array, wherein the calibration and configuration information isunique to each RF tile sub-array and the calibration and configurationinformation is downloaded from a configuration storage device on each RFtile sub-array through a tile control integrated circuit on each RF tilesub-array to the RF element compensation table; concurrently andseparately processing the data to provide unique control data to each RFtile sub-array of a plurality of RF tile sub-arrays (704), each RF tilesub-array comprising a multiplicity of RF elements, a multiplicity of RFintegrated circuits operatively connected to one or more of themultiplicity of RF elements, a tile control integrated circuitoperatively connected to each of the multiplicity of RF integratedcircuits, wherein the multiplicity of RF elements, the multiplicity ofRF integrated circuits, the tile control integrated circuit and theconfiguration storage device are disposed on a single associated RF tilesub-array and each RF element being separately controllable for steeringor tracking the RF beam generated by the RF element or received by theRF element based on the unique control data; and transmitting eachunique control data to a corresponding RF tile sub-array over an RF tilebus of a plurality of RF tile buses (706), wherein one RF tile bus ofthe plurality of RF tile buses is associated with each RF tile sub-arrayof the plurality of RF tile sub-arrays.
 19. The method of claim 18,further comprising: processing the unique control data by the tilecontrol integrated circuit of the RF tile sub-array (708) to provideindividual control information corresponding to each RF element of theRF tile sub-array; and transmitting the individual control informationto an RF integrated circuit associated with each RF element (710), theRF integrated circuit using the individual control information tocontrol the associated RF element for steering or tracking the RF beam.20. The phased array antenna system of claim 1, wherein the calibrationand configuration information that is unique to a particular RF tilesub-array is determined during factory testing and calibration andstored on the configuration storage device of the particular RF tilesub-array.